HEALTH-BRAZIL: Military Joins Anti-Dengue Offensive

By Mario Osava Reprint | | Print |

Mario Osava

RIO DE JANEIRO, Mar 7 2002 (IPS) - Some 1,300 Brazilian army and navy troops are joining the war against the mosquito population that is spreading dengue throughout Rio de Janeiro state, where the epidemic has reached unprecedented proportions.

The offensive, known as “D-Day against Dengue”, officially begins Saturday with the mobilisation of members of the military and volunteers in an attempt to reduce the incidence of the disease, which has already caused at least 27 deaths in this area since the epidemic began.

As of Wednesday, there have been 69,427 cases of dengue reported since the beginning of the year, 826 of which were haemorrhagic, the most serious manifestation of the disease. But health experts believe the true number of victims could be as much as five times higher, as many cases are never reported to the health authorities.

Haemorrhagic dengue is fatal in more than 20 percent of cases if the patient does not receive immediate and appropriate medical treatment. So far, there is no vaccine to prevent infection with any of the serotypes.

Individuals infected with dengue can suffer acute pain and high fever for one to two weeks, and those with haemorrhagic dengue require immediate hospitalisation.

The World Health Organisation (WHO) calculates that this modern plague threatens 2.5 billion people, or 40 percent of the global population. Dengue is almost completely urban in scope, unlike other diseases spread by mosquitoes, like malaria and yellow fever, and is so far limited to the Earth’s tropical and subtropical regions.

At the current rate of transmission, it is feared that a million people will be hit by the current wave of dengue in Rio de Janeiro state, home to 14 million people.

According to Sergio Arouca, public health physician and former secretary of health for the city of Rio de Janeiro, a major epidemic generally occurs one year after the arrival of a new type of dengue virus, to which the population has not developed immunity.

Once an individual has been infected with a strain of dengue, he or she becomes immune to that serotype.

In Brazil, dengue virus serotypes 1 and 2 were already present, but type 3 was first detected in the city of Rio in December 2000.

This sounded the alarm for intensive campaigns to take preventive actions, particularly to eliminate places where the Aedes aegypti, the mosquito that transmits the disease, can reproduce.

However, the resources designated for prevention were cut back, and the officials in charge of the effort were laid off, said Arouca.

The lack of coordination and cooperation among municipal, state and national authorities completed the circumstances favouring the worst dengue epidemic recorded in Brazil, a country that has suffered outbreaks since 1986 during the Southern Hemisphere summer months.

The magnitude of the problem has prompted a national offensive to save Rio. The Ministry of Health deployed 1,000 agents from throughout the country who are specialised in fighting epidemics. The local fire-fighting corps has made 5,000 members of the force available to assist the health authorities.

The 1,300 military troops joined this Aedes aegypti-fighting army Wednesday, a force that Health Minister Barjas Negri says now totals 16,000 people, including local officials and the volunteers mobilised by the non-governmental organisation Viva Rio.

The campaign entails door-to-door visits to homes and businesses that could have standing water on the premises, whether in puddles or in open containers, which serve as nurseries for mosquitoes.

Insecticide is to be applied where needed, and the population will receive instructions on how to prevent water from accumulating and how to avoid infection.

With this approach, and the grassroots “D-Day” mobilisation, Negri expects to reverse the trend of rising numbers of infections, and that new dengue cases will drop off sharply in April.

The dengue problem is less of a concern in the rest of the country, where the number of reported cases has fallen since last year, says the health official. The rise in the national figure is due solely to the epidemic in Rio de Janeiro, where more than half of the people infected this year live.

But so far, “the mosquitoes are winning the war,” and it is a fantasy to expect the insect will be eradicated, according to researchers.

An aggressive and continuous effort will be needed, as Brazilians will have to learn to live with the presence of the disease and prevent serious outbreaks like this year’s, Celso Ramos Filho, infectious disease specialist at the Federal University of Rio de Janeiro, told IPS.

Meanwhile, Hermann Schtzmayr, an expert with the Oswaldo Cruz Institute, warns that Brazil will have to prepare to deal with the inevitable arrival of dengue serotype 4, the only one that has not been detected inside the borders of this country. The institute was responsible for identifying the presence of the other strains of the disease when they first appeared in Rio.

Type 4 has been reported in neighbouring countries, such as Colombia and Venezuela, Schtzmayr said.

Most of the mosquito breeding sites are found in residential areas, according to health minister Negri. Particularly in Rio de Janeiro, where it is popular to keep ornamental plants in patios and on balconies. The plant pots with excess water serve as ideal nurseries for the Aedes aegypti, he said.

Furthermore, nearly a fifth of the homes in the city are unoccupied, making it more likely that there is standing water on the property and that the “mosquito-killing army” would not have any way to enter and apply insecticide.

There is the added problem of precarious sanitation services in Brazilian cities. Empty bottles, whether plastic or glass, used tyres, and all sorts of receptacles can be found dumped in public spaces, accumulating rainwater and turning into breeding grounds for the Aedes aegypti.

Without a broad mobilisation of city residents, it will be impossible to get rid of those millions of mosquito breeding sites, says Rubem Cesar Fernandes, Viva Rio coordinator.